Organic compounds, and more specifically pharmaceuticals, are generally more stable when they exist as a solid or powder than when they exist in solution. The shelf-life of a pharmaceutical stored in solution is generally shorter than the shelf-life of the pharmaceutical stored as a solid or powder. Since many pharmaceuticals are stored for extended periods of time before use, it is advantageous to have these pharmaceuticals remain active over the extended period of time. It is therefore desirable to store pharmaceuticals, over an extended period of time, as a solid or powder. This especially includes those pharmaceuticals that are ultimately reconstituted as a solution before administration.
Lyophilization is routinely used in the preparation and storage of pharmaceuticals. In such applications, lyophilization is usually carried out by freezing a solution containing the pharmaceutical, followed by sublimation to provide the solid or powder essentially free of solvent. Lyophilization directly in a vial or ampule requires transfer of the reconstituted pharmaceutical from the vial or ampule to a syringe. As such, a syringe is especially useful for the lyophilization of an injectable medication since the medication is ultimately administered from the syringe. Lyophilization can be performed wherein the solution containing the pharmaceutical is lyophilized directly in a syringe. See, U.S. application Ser. No. 09/190,341. The lyophilized pharmaceutical (i.e., medication) can then be stored in the syringe wherein a diluent can be added to the syringe for reconstitution of the medication just prior to administration. The medication can then be administered from the syringe directly to the patient.
Even though lyophilization of a solution directly in a syringe is useful, there exist serious drawbacks. Lyophilization typically results in the solution xe2x80x9cpoppingxe2x80x9d when there is a residual amount of solvent remaining. The popping can result in solvent and pharmaceutical being displaced outside the syringe. In addition, the popping can result in cross contamination of adjacent syringes in the array. When lyophilization is performed directly in a syringe, a significant amount of solution containing the pharmaceutical can be displaced outside the syringe. Accordingly, one cannot be certain whether any such pharmaceutical has been displaced outside the syringe and therefore the amount of pharmaceutical remaining inside the syringe after lyophilization may not be sufficiently accurate or precise. Thus, the syringe and the contents therein must be recycled or discarded since the amount of pharmaceutical remaining in the syringe cannot be adequately ascertained for proper administration.
Alternatively, a pharmaceutical can be introduced into a syringe directly as a solid or powder. The syringe is usually filled with the pharmaceutical with the use of powder filling equipment. The existing powder filling equipment, however, is not sufficiently accurate or precise to dispense a small amount of pharmaceutical necessary for administration. As such, there is a need for an apparatus that will allow for a relatively precise and accurate amount of pharmaceutical to be introduced into a syringe from a precise and accurate amount of solution containing the pharmaceutical.
The present invention provides a cover plate suitable for use to cover one or more delivery containers (e.g., syringe) during lyophilization. The cover plate of the present invention includes a lid region and one or more protuberances which project perpendicularly from the lid region. The one or more protuberances are adapted to fit in the one or more delivery containers. The cover plate permits the escape of vapor from the one or more delivery containers during the lyophilization process. In addition, the cover plate prevents the escape of lyophilizate from the one or more delivery containers during the lyophilization process.
The present invention also provides a system for lyophilizing a pharmaceutical solution. The system includes one or more delivery containers suitable for containing the pharmaceutical solution. The system also includes a cover plate of the present invention.
The present invention also provides another system for lyophilizing a pharmaceutical solution. The system includes a lyophilizing apparatus and one or more delivery containers. At least one of the one or more delivery containers contains the pharmaceutical solution. The system also includes a cover plate of the present invention that covers the one or more delivery containers during the lyophilization process.
The present invention also provides a method for lyophilizing a pharmaceutical solution. The method includes depositing the solution in one or more delivery containers, covering the one or more delivery containers with a cover plate of the present invention, and lyophilizing the solution that includes the pharmaceutical. The cover plate allows pharmaceutical solutions to be lyophilized while preventing cross contamination of adjacent syringes. In addition, the cover plate allows pharmaceutical solutions to be lyophilized while the amount of lyophilizate remaining inside the delivery containers is sufficiently ascertainable.